I have a waterproof but flexible transparent plastic case for it. I can use the iPhone above water though the case but underwater only the physical buttons work, the touch screen does not respond. Why is this and is there anyway to overcome this without me having to crawl into the case with it.
(Not that I’m planning to use it this way, but was testing out the waterproof case and noticed this)
Also will the data,cellular and gps antennas work while submerged?
Water is a pretty effective attenuator for electromagnetic radiation. You won’t pick up any cellular, wifi or gps signals while submerged.
The iPhone (and all other quality smartphones) use capacitive touch screens. Presumably, they won’t work when submersed in a conductive liquid (it would be like touching the entire screen at once).
My sister used her iPhone in its waterproof case to take underwater pics. Which would mean she had to be able to use the touchscreen underwater. So it is possible.
No you can use the ‘+’ button on the side to snap photo’s but you would have to set up the photo app above water ahead of time from what I’m seeing.
Not necessarily. The last couple of versions of iOS allow the volume button to be used as the camera button.
I have a Uniden Submersible cordless phone in my bathroom. It’s not obvious how I would actually use it underwater since I hold my breath while I’m under water. I assume it would work underwater but it’s possible that they are claiming only that it would survive.
I’ve never been on a submarine, but on TV they are depicted using radio underwater. Is that just jive? As I think about it, it seems like any antenna would be grounded.
So is it true? No radio at all underwater?
The attenuation is frequency-dependent, so they can use Very Low Frequency radio, but the data rate is slow. Otherwise they can send up a floating antenna, which might what you see on TV.
I have a case like this for my iPod touch and I’m 90% sure I’ve used the touch screen underwater. Maybe it’s just a function of the case, and not the phone?
I’ll try to remember to try it next Friday when I swim, and come back to let you know 
You can have these guys dip it in magic goo (sort of) and make it waterproof (again, sort of)…
This. I have an Android phone and if I talk on it while I’m sweaty, the screen refuses to respond to any input until I wipe the liquid off the screen. So I assume that this would be the reason.
When closer to the surface, subs can extend an antenna from the mast. At deeper depths they can deploy a long wire antenna.
It seems certain cases don’t work well with the screen. This one uses some kind of gel pad to make the touch sensitivity work.
Yes I saw something similarly stated with another case, in that one there is a vacuum pump that you evacuate the air from the case to make the screen usable.
So assuming a non-pressurized flexible screen case, to what depth can a iPhone make it?
Nevermind, wrong thread